|Better Farming Series 16 - Roots and Tubers (FAO - INADES, 1977, 58 p.)|
|How to grow yams|
Before planting yams, the soil must be well prepared.
- Clear the land before the rainy season. Cut down the trees, cut the branches. Stack the trees and branches and burn them.
Do not cut all the trees. Leave some of the little ones. They can be used as supports for the aerial stems of the yams. These natural supports will later be supplemented by stakes.
- Till the land to a depth of 20 to 40 centimetres.
- At this time add organic manures, well- rotted farmyard manure, compost or green manure, at 10 to 40 tons a hectare.
Inorganic fertilizers may be used to get a greater yield.
The amounts vary according to the country, region, or even the soils in the same field.
Research stations like IRAT' make a special study of food crops,
and advise farmers.
In Liberia, it is known that the application of potassium (K) fertilizers is valuable in increasing yields.
In Nigeria and Ghana, the agricultural service advises that yams should be given the following fertilizers:
250 kg/ha ammonium sulphate;
65 kg/ha single superphosphate;
215 kg/ha potassium chloride.
The farmer who wants to make progress should all the time ask for advice from the agricultural service.
- In many African countries, yams are planted in mounds 30 to 40 centimetres high and 1 or 2 metres apart. These mounds are made at the beginning of the rainy season. The soil which has thus been well loosened holds plenty of water.
Sometimes the mounds are only made 2 or 3 months after planting. This earthing up encourages the development of tubers but takes a lot of work from the farmer.
If the soil is fairly deep and is deeply tilled, it is not always necessary to make mounds. In that case, more tubers can be planted and the density is greater.
Yams are planted at the beginning of the rainy season. Plant them 5 to 10 centimetres deep 1 metre apart in all directions or 90 centimetres by 1 metre. This gives the tubers plenty of room to fatten up, and the plant makes use of all the rainy season water.